Abstract

Background

Treatment goals for knee osteoarthritis (OA) include preservation of mobility, control of pain, and delaying total knee replacement (TKR).

Objective

To estimate the cost-effectiveness of viscosupplementation (hylan G-F 20) alone compared with conventional supportive therapy (CST) in the treatment of knee OA in Colombia.

Methods

Microsimulation in patients with knee OA, modeling of clinical outcomes (disease progression, symptom improvement, TKR), and estimation of associated costs were performed (drugs, diagnostic tests, procedures, and hospitalizations). The probabilities for disease progression and clinical events were correlated with patients’ characteristics. Clinical outcome information was obtained from the literature. The costs were drawn from institutional databases from health maintenance organizations and the Colombian standard tariffs handbook (ISS 2001. Agreement No. 256 of 2001. Tariffs for the health promoter Social Security EPS-ISS. Social Insurance Board of Directors. December 19, 2001). Sensitivity analyses were performed for costs and transition probabilities.

Results

Monte-Carlo simulation for 1000 patients with knee OA showed that viscosupplementation with hylan G-F 20 delayed the occurrence of TKR by 3 years compared with CST. Western Ontario and McMaster Universities Arthritis Index scores indicate improvement in symptoms and function with hylan G-F 20. The incremental cost-effectiveness ratio for viscosupplementation is dominant, with reduction of US $576 in treatment cost in favor of hylan G-F 20, with more cost-effectiveness per quality-adjusted life-year during the first 10 years of treatment compared with CST.

Conclusions

The results of mathematical simulation indicate that in comparison to conventional support therapies, viscosupplementation with hylan G-F 20 improved disease symptoms, joint function, and quality of life, reduced direct treatment costs, delayed TKR by 3 years, and was cost-effective in Colombia.